1) Usually, reject bearings and bushings that have internal diameterical play of 0.010 inch. But, use service experience and the applicable permitted wear limits to know if the part is serviceable.
(b)
Examine the lining load pattern.
1) Examine the surface where the lining and ball/pin touch. Make sure all of the surface has an equal load.
NOTE: Incorrect swaging during manufacture or installation
____ can cause the edges of the lining to wear too much. These bearings and bushings are not serviceable.
(c)
Examine the lining for unwanted material.
1) Examine the lining to make sure that no unwanted material became attached.
(d)
Examine the lining for chemical deterioration.
1) Examine the lining and lining bond for signs of chemical damage.
S 216-008
(5) Do the Bearing/Bushing - Inspection/Check (Bench Check) task.
TASK 20-20-21-206-009
3. Special Bearing and Bushing Configurations Inspection/Check
___________________________________________________________
A. Procedure - Special Bearing and Bushing Configurations - Check
S 216-010
(1)
Examine aluminum bearing races for serviceable surface treatment or plating, and for corrosion and cracks.
S 216-011
(2)
Examine special configuration bearings with threads, holes, keyways, flanges, or equivalent properties for cracks in these areas.
NOTE: These special configurations can cause stress risers in these
____
areas.
S 216-012
(3) Do the Bearing/Bushing - Inspection/Check (Bench Check) task.
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
20-20-21
ALL ú ú 01 Page 603 ú Nov 15/91
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A 737-300/400/500MAINTENANCE MANUAL
TASK 20-20-21-206-013
4. Bushings and Bearings (Bench Check) - Inspection/Check
______________________________________________________
A. General
(1)
Before you do this task, do the procedure - Check of Self-Lubricated Bearings and Bushings (Bench Check) in the first task.
B.
Procedure - Wear Check
S 226-014
(1) To determine the amount of bearing wear, manually apply a reversing load to bearing in a simple holding fixture and measure play with a dial indicator. Radial wear should be measured by applying a reversing radial load of 10 to 15 pounds and total diametrical play measured. A reversing load of the same magnitude should then be applied in an axial (thrust) direction and axial play measured.
NOTE: When measuring play in the radial direction, several points
____ should be checked by rotating the outer race relative to the inner race to establish the point where maximum play exists before attempting to make an accurate wear reading.
C. Procedure - Bearing Breakaway Torque on Spherical Bearing Check
S 226-015
(1) To do the breakaway preload torque checks, measure the torque necessary to turn one race with the other contamination race.
NOTE: The bearing must not have lubricants or other contamination.
____ The breakaway torque must not be more than twice the permitted rotational preload torque (Table 601).
NOTE: Measure the breakaway torque before you do the rotational
____ torque checks. Do the test at room temperature.
D. Procedure - Bearing Rotational Torque on Spherical Bearing Check
S 226-016
(1) To do the rotational preload torque checks, measure the torque necessary to turn one race with the other race held.
NOTE: The bearing must not have lubricants or other contamination.
____ See Table 601 for permitted rotational preload torque values.
NOTE: Measure the breakaway torque before you do the rotational
____ torque checks. For rotational torque tests, you must turn the bearing through two or three full turns immediately before you measure the torque. Do the tests at room temperature.
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